Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Mazda’s rotary engine in the age of the electric car

nippon.com

Post reply on HN
Print view View original

291–295 of 295 posts

Re: Mazda’s rotary engine in the age of the electric car

#291

Post by dontlaugh »

narag wrote: post #87
ggreer wrote: post #60

Earlier quoted context omitted.

Several reasons. First, like most of the Japanese manufacturers, Mazda bet against electric vehicles. They focused R&D on improving engine efficiency and getting their engines to run on hydrogen. If Mazda wants to make electric vehicles now, they have to play catch-up, or license key technologies from other manufacturers. Second, batteries are heavy. For sedans and mid-size crossovers, this isn't much of a problem. E…

It seems Mazda is going ahead with an electric Miata, they just don't know how electric it will be: https://www.motortrend.com/news/2026-mazda-mx-5-miata-electr...

I think it’s likely to be a mild hybrid.

Re: Mazda’s rotary engine in the age of the electric car

#292

Post by suprjami »

_ea1k wrote: post #283
suprjami wrote: post #102

Earlier quoted context omitted.

It really isn't. Go and drive a 13BT car. They make almost all their torque by 2500rpm and the curve is flat. They're more torquey than any 4 cylinder I've driven.

I've owned an RX-7 and an RX-8. They definitely didn't have flat torque curves. Even the twin sequential setup on the FC was far from flat. But even if it was, that was the most powerful stock configuration made and it topped out at ~184 lb/ft. :) Torque was never the strength of this motor.

I had a turbo FC and beg to differ. A dyno graph of a stock car also begs to differ.

Re: Mazda’s rotary engine in the age of the electric car

#293

Post by dunekid »

The fortnine video about this type of engine is quite interesting:https://youtu.be/-3HBAvkc4a0?feature=shared Mazda might be one company with the expertise to make it work. The range extender, not directly driving wheels, can work in its optimum temperature, rpm and on a pretty constant load. The ability to work with multiple types of fuel adds to its versatility as a range extender. Since Mazda has alliances with other Japanese car makers, if it is indeed a good proposition, I reckon it would appear on other Japanese cars too, and maybe in BMW as well.

Re: Mazda’s rotary engine in the age of the electric car

#294

Post by _ea1k »

suprjami wrote: post #292
_ea1k wrote: post #283

Earlier quoted context omitted.

I've owned an RX-7 and an RX-8. They definitely didn't have flat torque curves. Even the twin sequential setup on the FC was far from flat. But even if it was, that was the most powerful stock configuration made and it topped out at ~184 lb/ft. :) Torque was never the strength of this motor.

I had a turbo FC and beg to differ. A dyno graph of a stock car also begs to differ.

Dyno graphs aren't consistent with that:

https://www.google.com/imgres?q=1993%20stock%20rx-7%20dyno&i...

They are fun engines, but low end torque just isn't their thing.

Re: Mazda’s rotary engine in the age of the electric car

#295

Post by ghostly_s »

ryukoposting wrote: post #164
ghostly_s wrote: post #159

Earlier quoted context omitted.

> The Wankel is at its most efficient and its most reliable when operating at a constant RPM. Conveniently, the EV generator application demands a pretty flat RPM band. If I understand the article correctly, the "series" hybrid configuration means precisely that it cannot operate at the ideal rpm when charging the battery, because it is always driving the wheels directly as well.

Exactly the opposite. In a series hybrid, there is no mechanical connection between the engine and the wheels - only an electrical one, with the battery still providing considerable power in most cases, even when it's depleted. No hybrid ever runs its battery all the way to zero, and series hybrids are no exception. The Chevy Volt (the other notable series hybrid in Western markets) keeps its engine at a near-constan…

The part that's got me confused is the illustration near the end, with the caption: "In the MX-30 e-Skyactiv R-EV’s electric propulsion unit, the already compact rotary engine shares a common axle with the generator and motor."

I don't get how the engine can be decoupled from the wheels if it's mounted to the same axle as the motor?

Post reply on HN